1. Field of the Invention
The present invention generally relates to an electron microscope and in particular to an electron microscope which is combined with an optical microscope so that a same specimen can be exchangeably observed through both microscopes.
2. Description of the Prior Art
An optical microscope permits observation of a specimen in respect of color and structure thereof. However, the resolution power of the optical microscope is far lower than that of an electron microscope. Although the latter is capable of observing a fine structure of the specimen, it is impossible to observe the coloration of the specimen. Such being the circumstances, separate observations through the optical microscope and the electron microscope are required when a specimen is to be examined in respect of coloration and structure, which means very troublesome procedure. Besides, when a fragmental portion of a specimen has to be analyzed, a high skillfulness is required in order to accurately align the specimen at predetermined positions of the optical microscope and the electron microscope so that the same portion of the specimen in concern can be correctly observed through both microscopes. Thus, there is a great demand for electron microscope which is combined with an optical microscope in such a manner that one and the same specimen can be interchangeably or exchangeably placed at predetermined positions in the optical and the electron microscopes through simple manipulation.